1. Field of the Invention
The present invention relates to a speech recognition system for simultaneous recognition of speeches from multiple sources and a method for generating a mask for the speech recognition system.
2. Description of the Related Art
The technology of simultaneous recognition of speeches from multiple sources is important for robots that work in the real environment. A speech recognition system for simultaneous recognition of speeches from multiple sources separates speeches according to sources and performs speech recognition using the acoustic feature of a separated speech. In speech recognition a mask prepared according to reliability of separation is used for each acoustic feature (for example, Reference 2). Conventionally hard masks which are binary, taking a value of 0 or 1 are used as such masks (for example, Reference 3). Although soft masks which take continuous values between 0 and 1 are known (for example, Reference 4), a soft mask used for a speech recognition system for simultaneous recognition of speeches from multiple sources has not been developed. The reason is that conventionally those skilled in the art thought that hard masks are more appropriate for a speech recognition system for simultaneous recognition of speeches from multiple sources than soft masks (for example, Reference 2). Thus, a speech recognition system provided with a soft mask appropriately designed for simultaneous recognition of speeches from multiple sources and having an increased speech recognition rate has not been developed.
Accordingly, there is a need for a speech recognition system provided with a soft mask appropriately designed for simultaneous recognition of speeches from multiple sources and having a higher speech recognition rate has not been developed.